1806, 13 May 1806 edition of Balance and Columbian Repository, published by Hudson, New York, (first appearance in print):

Cocktail is a stimulating liquor composed of spirits of any kind, sugar, water, and bitters — it is vulgarly called a bittered sling and is supposed to be an excellent electioneering potion, inasmuch as it renders the heart stout and bold, at the same time that it fuddles the head.